Updated publication reference for PubMed record(s): 30645593.Salmonella Typhimurium ST313 is associated with invasive nontyphoidal salmonellosis (iNTS) disease in sub-Saharan Africa. Using ST313 isolate, D23580, and the well-characterized ST19 isolate 4/74, that causes gastroenteritis across Europe, we generated transcriptomic data from sixteen infection-relevant in vitro conditions and during infection of murine macrophages (http://bioinf.gen.tcd.ie/cgi-bin/jay/salcom_v2.pl?db=salcom_africa_new_HL). The transcriptional response of the two S. Typhimurium pathovariants to environmental stress was broadly similar. Comparative gene expression analysis identified virulence and metabolic genes that were up/down-regulated in D23580 versus 4/74. Findings were backed up by proteomic analysis, with12 genes being differentially-expressed at both the transcriptional and protein levels including melA and cysS. The data led us to discover that the ablation of melibiose utilization was caused by 3 SNP mutations in D23580 and to identify a novel plasmid-maintenance system involving a plasmid-encoded CysS cysteinyl-tRNA synthetase. Our functional transcriptomic analysis represents a powerful tool for identification of key phenotypic differences between bacterial pathovariants.